<title>dnsjava examples</title>

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<h1 align="center">dnsjava examples</h1>

All of these examples are code fragments. Code using these fragments should

check exceptions when appropriate, and should:

<pre><code>import org.xbill.DNS.*;</code></pre>

<p><b>Get the IP address associated with a name:</b></p>

InetAddress addr = Address.getByName("www.dnsjava.org");

<p><b>Get the MX target and preference of a name:</b></p>

Record [] records = new Lookup("gmail.com", Type.MX).run();

for (int i = 0; i &lt; records.length; i++) {

MXRecord mx = (MXRecord) records[i];

System.out.println("Host " + mx.getTarget() + " has preference " + mx.getPriority());

}

<p><b>Query a remote name server for its version:</b></p>

Lookup l = new Lookup("version.bind.", Type.TXT, DClass.CH);

l.setResolver(new SimpleResolver(args[0]));

l.run();

if (l.getResult() == Lookup.SUCCESSFUL)

System.out.println(l.getAnswers()[0].rdataToString());

<p><b>Transfer a zone from a server and print it:</b></p>

ZoneTransferIn xfr = ZoneTransferIn.newAXFR(new Name("."), "192.5.5.241", null);

List records = xfr.run();

for (Iterator it = records.iterator(); it.hasNext(); )

System.out.println(it.next());

<p><b>Use DNS dynamic update to set the address of a host to a value specified on the command line:</b></p>

Name zone = Name.fromString("dyn.test.example.");

Name host = Name.fromString("host", zone);

Update update = new Update(zone);

update.replace(host, Type.A, 3600, args[0]);

Resolver res = new SimpleResolver("10.0.0.1");

res.setTSIGKey(new TSIG(host, base64.fromString("1234")));

res.setTCP(true);

Message response = res.send(update);

<p><b>Manipulate domain names:</b></p>

Name n = Name.fromString("www.dnsjava.org");

Name o = Name.fromString("dnsjava.org");

System.out.println(n.subdomain(o)); // True

System.out.println(n.compareTo(o)); // &gt; 0

Name rel = n.relativize(o); // the relative name 'www'

Name n2 = Name.concatenate(rel, o);

System.out.println(n2.equals(n)); // True

// www

// dnsjava

// org

for (int i = 0; i &lt; n.labels(); i++)

System.out.println(n.getLabelString(i));